# Gamma Tauri

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> Markdown URL: https://mediated.wiki/source/Gamma_Tauri.md
> Source: https://en.wikipedia.org/wiki/Gamma_Tauri
> Source revision: 1319262639
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{{Short description|Multiple star in the constellation Taurus}}
{{Starbox begin
 | name     = γ Tauri
}}
{{Starbox image
 | image=
{{Location mark
|image=Taurus constellation map.svg|alt=|float=center|width=260
|label=|position=right
|mark=Red circle.svg|mark_width=10|mark_link=γ Tau
|x=607|y=566
}}
|caption=Location of γ Tauri (circled)
}}
{{Starbox observe
 | epoch    = J2000
 | ra       = {{RA|04|19|47.6037}}<ref name="hipparcos"/>
 | dec      = {{DEC|+15|37|39.512}}<ref name="hipparcos" />
 | appmag_v = 3.654<ref name="SIMBAD" />
 | constell = [Taurus](/source/Taurus_(constellation))
}}
{{Starbox character
 | type     = [red clump](/source/red_clump)<ref name=db2001/>
 | class    = G8III<ref name="pasj60" />
 | b-v      = +0.99<ref name="yerkes53"/>
 | u-b      = +0.84<ref name="yerkes53" />
 | variable = 
}}
{{Starbox astrometry
 | radial_v = {{nowrap|38.7 ± 0.9}}<ref name=rgcrv/>
 | prop_mo_ra  = +115.29<ref name="hipparcos" />
 | prop_mo_dec = -23.86<ref name="hipparcos" />
 | parallax = 21.17
 | p_error  = 1.17
 | parallax_footnote = <ref name="hipparcos" />
 | absmag_v = 0.22<ref name="pasj60" />
}}
{{Starbox detail
 | mass     = {{nowrap|2.70 ± 0.13}}<ref name="aaa458" />
 | radius   = {{nowrap|13.4 ± 0.2}}<ref name="apj691" />
 | luminosity  = 85<ref name="pasj60" />
 | temperature = {{nowrap|4,844 ± 47}}<ref name="apj691" />
 | metal_fe = +0.11<ref name=aaa480_1_91/>
 | rotational_velocity = 4<ref name=coapa239_1/>
 | rotation = 253&nbsp;days<ref name=aaa421_241/>
 | gravity  = 2.58-2.61<ref name="apj691" />
 | age_myr  = 430–530<ref name="pasj60" /><ref name="aaa458" />
}}
{{Starbox catalog
 | names = Prima Hyadum, Hyadum I,<ref name="hinckley" /> 54 Tauri, [BD](/source/Star_catalogue)+15°612, [FK5](/source/Fifth_Fundamental_Catalogue) 159, [HD](/source/Henry_Draper_Catalogue) 27371, [HIP](/source/Hipparcos_catalogue) 20205, [HR](/source/Harvard_Revised_catalogue) 1346, [SAO](/source/Star_catalogue) 93868, GC 5226, [WDS](/source/Washington_Double_Star_Catalog) 04198+1538<ref name="SIMBAD"/>
}}
{{Starbox reference|Simbad=gam+Tau}}
{{Starbox end}}
'''Gamma Tauri''' ('''γ Tauri''', abbreviated '''Gamma Tau''', '''γ Tau''') is either a solitary, [binary](/source/binary_star) or [double star](/source/double_star) (the [Washington Double Star Catalog](/source/Washington_Double_Star_Catalog) notes it as a "Dubious Double" or "Bogus Binary"<ref name="WDS">{{cite web | url=http://ad.usno.navy.mil/wds/ | title=Washington Double Star Catalog | publisher=United States Naval Observatory | access-date=2 January 2018 | archive-url=https://web.archive.org/web/20110214155533/http://ad.usno.navy.mil/wds/ | archive-date=14 February 2011 | url-status=dead }}</ref>) that marks the tip of the "V" in the [constellation](/source/constellation) of [Taurus](/source/Taurus_(constellation)). It is a member of, and located within about 2.5 [parsec](/source/parsec)s of the center of, the [Hyades star cluster](/source/Hyades_(star_cluster)), the nearest [open cluster](/source/open_cluster) to the Sun. Based upon [parallax](/source/parallax) measurements, Gamma Tauri is approximately 154 [light-year](/source/light-year)s from the [Sun](/source/Sun).

Considered as a pair of stars, the two components are designated Gamma Tauri A (officially named '''Prima Hyadum''' {{IPAc-en|,|p|r|ai|m|@|_|'|h|ai|@|d|@|m}}, the traditional name for the system)<ref name="IAU-LSN">{{cite web | url=https://www.iau.org/public/themes/naming_stars/ | title=Naming Stars | publisher=IAU.org | access-date=16 December 2017 | archive-date=10 March 2025 | archive-url=https://web.archive.org/web/20250310063743/https://www.iau.org/public/themes/naming_stars/ | url-status=dead }}</ref> and B.

== Nomenclature ==

''γ Tauri'' ([Latinised](/source/Latinisation_of_names) to ''Gamma Tauri'') is the system's [Bayer designation](/source/Bayer_designation). The designations of the two potential components as ''Gamma Tauri A'' and ''B'' derive from the convention used by the Washington Multiplicity Catalog (WMC) for [multiple star system](/source/Star_system)s, and adopted by the [International Astronomical Union](/source/International_Astronomical_Union) (IAU).<ref name="planetnaming">{{cite arXiv |title=On the naming convention used for multiple star systems and extrasolar planets |date=2010 |eprint=1012.0707 |class=astro-ph.SR |last1= Hessman |first1=F. V. |last2= Dhillon |first2=V. S. |last3= Winget |first3=D. E. |last4= Schreiber |first4=M. R. |last5= Horne |first5=K. |last6= Marsh |first6=T. R. |last7= Guenther |first7=E. |last8= Schwope |first8=A. |last9= Heber |first9=U. }}</ref>

Gamma Tauri bore the traditional name ''Hyadum I'',<ref name="hinckley">{{cite book | last=Allen | first=R. H. | date=1963 | author-link=Richard Hinckley Allen | title=[Star Names: Their Lore and Meaning](/source/Star_Names%3A_Their_Lore_and_Meaning) | edition=Reprint | publisher=Dover Publications Inc. | location=New York, NY | isbn=0-486-21079-0 | page=[https://archive.org/details/starnamestheirlo00alle/page/390 390] }}</ref> which is [Latin](/source/Latin) for "First of the Hyades". In 2016, the IAU organized a [Working Group on Star Names](/source/IAU_Working_Group_on_Star_Names) (WGSN)<ref name="WGSN">{{cite web | url=https://www.iau.org/science/scientific_bodies/working_groups/280/ | title=IAU Working Group on Star Names (WGSN) | access-date=22 May 2016 | archive-date=30 March 2019 | archive-url=https://web.archive.org/web/20190330194042/https://www.iau.org/science/scientific_bodies/working_groups/280/ | url-status=dead }}</ref> to catalog and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire [multiple systems](/source/multiple_star).<ref name="TriRpt18">{{cite web | url=https://www.iau.org/static/science/scientific_bodies/working_groups/280/wg-starnames-triennial-report-2015-2018.pdf | page=5 | title=WG Triennial Report (2015-2018) - Star Names | access-date=2018-07-14 | archive-date=2019-08-23 | archive-url=https://web.archive.org/web/20190823174756/https://www.iau.org/static/science/scientific_bodies/working_groups/280/wg-starnames-triennial-report-2015-2018.pdf | url-status=dead }}</ref> It approved the name ''Prima Hyadum'' for the component Gamma Tauri A on 5 September 2017 and it is now so included in the List of IAU-approved Star Names.<ref name="IAU-LSN"/>

In [Chinese](/source/Chinese_astronomy), {{lang|zh|畢宿}} ({{lang|zh-Latn|Bì Xiù}}), meaning ''[Net](/source/Net_(Chinese_constellation))'', refers to an [asterism](/source/Asterism_(astronomy)) consisting of Gamma Tauri, [Epsilon Tauri](/source/Epsilon_Tauri), [Delta³ Tauri](/source/Delta3_Tauri), [Delta¹ Tauri](/source/Delta1_Tauri), Alpha Tauri ([Aldebaran](/source/Aldebaran)), [71 Tauri](/source/71_Tauri) and [Lambda Tauri](/source/Lambda_Tauri).<ref>{{in lang|zh}} ''中國星座神話'', written by 陳久金. Published by 台灣書房出版有限公司, 2005, {{ISBN|978-986-7332-25-7}}.</ref> Consequently, the [Chinese name](/source/Chinese_star_names) for γ Tauri itself is {{lang|zh|畢宿四}} ({{lang|zh-Latn|Bì Xiù sì}}), "the Fourth Star of Net".<ref>{{in lang|zh}} [http://www.lcsd.gov.hk/CE/Museum/Space/Research/StarName/c_research_chinengstars_ala_alz.htm 香港太空館 - 研究資源 - 亮星中英對照表] {{webarchive|url=https://web.archive.org/web/20081025110153/http://www.lcsd.gov.hk/CE/Museum/Space/Research/StarName/c_research_chinengstars_ala_alz.htm |date=2008-10-25 }}, Hong Kong Space Museum. Accessed on line November 23, 2010.</ref>

== Properties ==

Gamma Tauri presents as a [spectral class G8 or K0](/source/stellar_classification)<ref name="SIMBAD" /><ref name="pasj60" /> [giant star](/source/giant_star) with an [apparent magnitude](/source/apparent_magnitude) of +3.65. This star has passed through the [main sequence](/source/main_sequence) phase is now a [red clump](/source/red_clump) giant, meaning it is using nuclear fusion of [helium](/source/helium) at its core to provide energy.<ref name=db2001>{{cite journal
  | author1=de Bruijne, J. H. J.  |author2=Hoogerwerf, R. |author3=de Zeeuw, P. T.
  | title=A Hipparcos study of the Hyades open cluster. Improved colour-absolute magnitude and Hertzsprung-Russell diagrams
  | journal=[Astronomy and Astrophysics](/source/Astronomy_and_Astrophysics) | volume=367
  | issue=1
  | pages=111–147 |date=February 2001
  | doi=10.1051/0004-6361:20000410 | bibcode=2001A&A...367..111D|arxiv = astro-ph/0011565 |s2cid=55224801 }}</ref> 
Age estimates for Gamma Tauri range from 430&nbsp;million<ref name="pasj60">{{cite journal
  | author1=Takeda, Yoichi |author2=Sato, Bun'ei |author3=Murata, Daisuke
  | title=Stellar Parameters and Elemental Abundances of Late-G Giants | journal=Publications of the Astronomical Society of Japan |date=August 2008
  | volume=60 | issue=4 | pages=781–802
  | bibcode=2008PASJ...60..781T | arxiv = 0805.2434 | doi=10.1093/pasj/60.4.781 |s2cid=16258166 }}</ref> to 530&nbsp;million years.<ref name="aaa458">{{cite journal
  | author=da Silva, L.
  | title=Basic physical parameters of a selected sample of evolved stars
  | journal=Astronomy and Astrophysics | volume=458
  | issue=2 |date=November 2006 | pages=609–623 
  | doi=10.1051/0004-6361:20065105 |display-authors=etal | bibcode=2006A&A...458..609D|arxiv = astro-ph/0608160 | s2cid=9341088
 }}</ref> By comparison, the age of the Hyades cluster is about 625 million years with an error margin of 50 million years.<ref name="aaa458" />

The [angular diameter](/source/angular_diameter) of this star has been measured using the [CHARA array](/source/CHARA_array) to 2% accuracy. After correcting for [limb darkening](/source/limb_darkening), this gives the stellar radius as 13.4 times the [radius of the Sun](/source/solar_radius).<ref name="apj691">{{cite journal
  | author=Boyajian, Tabetha S. |display-authors=etal
  | title=Angular Diameters of the Hyades Giants Measured with the CHARA Array |date=February 2009
  | journal=The Astrophysical Journal | volume=691
  | issue=2 | pages=1243–1247
  | doi=10.1088/0004-637X/691/2/1243 | bibcode=2009ApJ...691.1243B|arxiv = 0810.2238 |s2cid=17092177
 }}</ref> The star is radiating about 85 times the [luminosity of the Sun](/source/solar_luminosity)<ref name="pasj60" /> and has 2.7 times the [Sun's mass](/source/solar_mass).<ref name="aaa458" /> With its large size and low [projected rotational velocity](/source/projected_rotational_velocity) of {{nowrap|4 km s<sup>−1</sup>}},<ref name=coapa239_1/> it takes about 253&nbsp;days to complete a rotation.<ref name=aaa421_241/>

==References==
{{reflist|30em|refs=

<ref name="hipparcos">{{citation | display-authors=1 | last1=Perryman | first1=M. A. C. | last2=Lindegren | first2=L. | last3=Kovalevsky | first3=J. | last4=Hoeg | first4=E. | last5=Bastian | first5=U. | last6=Bernacca | first6=P. L. | last7=Crézé | first7=M. | last8=Donati | first8=F. | last9=Grenon | first9=M. | title=The Hipparcos Catalogue | journal=Astronomy & Astrophysics | date=1997 | volume=323 | pages=L49–L52 | bibcode=1997A&A...323L..49P }}</ref>

<ref name="yerkes53">{{cite journal | last1=Johnson | first1=H. L. | last2=Morgan | first2=W. W. | title=Fundamental stellar photometry for standards of spectral type on the revised system of the Yerkes spectral atlas | journal=Astrophysical Journal | date=1953 | volume=117 | pages=313–352 | bibcode=1953ApJ...117..313J | doi=10.1086/145697 }}</ref>

<ref name=rgcrv>{{cite conference | last=Evans | first=D. S. | date=June 20–24, 1966 | editor1=Batten, Alan Henry  |editor2=Heard, John Frederick | title=The Revision of the General Catalogue of Radial Velocities | book-title=Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30 | location=University of Toronto | publisher=[International Astronomical Union](/source/International_Astronomical_Union) | bibcode=1967IAUS...30...57E }}</ref>

<ref name=aaa480_1_91>{{cite journal |author1=Soubiran, C. |author2=Bienaymé, O. |author3=Mishenina, T. V. |author4=Kovtyukh, V. V. | title=Vertical distribution of Galactic disk stars. IV. AMR and AVR from clump giants | journal=Astronomy and Astrophysics | volume=480 | issue=1|date=March 2008 | pages=91–101 | doi=10.1051/0004-6361:20078788 | bibcode=2008A&A...480...91S |arxiv = 0712.1370 |s2cid=16602121 }}</ref>

<ref name=coapa239_1>{{cite journal |author1=Bernacca, P. L. |author2=Perinotto, M. | title=A catalogue of stellar rotational velocities | journal=Contributi Osservatorio Astronomico di Padova in Asiago | volume=239 | issue=1 | date=1970 |page=1 | bibcode=1970CoAsi.239....1B }}</ref>

<ref name=aaa421_241>{{citation | display-authors=1 | last1=Setiawan | first1=J. | last2=Pasquini | first2=L. | last3=da Silva | first3=L. | last4=Hatzes | first4=A. P. | last5=von der Lühe | first5=O. | last6=Girardi | first6=L. | last7=de Medeiros | first7=J. R. | last8=Guenther | first8=E. | title=Precise radial velocity measurements of G and K giants. Multiple systems and variability trend along the Red Giant Branch | journal=Astronomy and Astrophysics | volume=421 | pages=241–254 |date=July 2004 | doi=10.1051/0004-6361:20041042-1 | bibcode=2004A&A...421..241S | doi-access=free }}</ref>

<ref name="SIMBAD">{{cite web | title=NSV 1553 - Variable Star  | publisher=[Centre de Données astronomiques de Strasbourg](/source/Centre_de_Donn%C3%A9es_astronomiques_de_Strasbourg) | work=SIMBAD | url=http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=NSV+1553 | access-date=2009-09-22 }}</ref>

}}

{{Stars of Taurus}}

{{Authority control}}

Category:G-type giants
Category:Horizontal-branch stars
Category:Hyades (star cluster)
Category:Taurus (constellation)
Prima Hyadum
Tauri, Gamma
Category:Durchmusterung objects
Tauri, 054
027371
020205
1346
Category:Population I stars

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Adapted from the Wikipedia article [Gamma Tauri](https://en.wikipedia.org/wiki/Gamma_Tauri) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Gamma_Tauri?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.